WORLD AND WORKS : FUTURE ESSAY

President Biden opened his first foreign trip recently be declaring that on issues like climate, ''the United States is back.''

After four years in which President Donald J Trump mocked the established science of climate change, discouraged the development of clean energy while favoring fossil fuels and refused to cooperate with allies on environmental issues, Mr. Biden was once again part of a unanimous consensus that the world needs to take drastic action to prevent a global disaster.

''President Biden has committed to tackling the climate crisis at home and abroad, rallying the rest of the world at the leaders summit, G7, and beyond to reach for bold targets within the next decade,'' said Daleep Singh, deputy national security adviser.

''While the previous administration ignored science and the consequences of climate change, our administration has taken unprecedented actions to prioritize this on the global stage.''

In addition to rejoining the 2015 Paris Agreement that Mr. Trump abandoned, Mr. Biden has promised to cut the United States greenhouse gas emissions by 50 percent to 52 percent below the 2005 levels by 2030 and to eliminate fossil fuel emissions from America's power sector by 2035.

But it was the United Kingdom, along with some other, European countries, that pushed aggressively during the summit this year to stop burning coal electricity by a specific date in the 2030s.

Burning coal is the largest source of carbon dioxide emissions, and after a pandemic year retreat, demand for coal is expected to rise by 4.5 percent this year, according to the International Energy Agency.

Instead, the final language of the leaders ''communique'' makes only a vague call to ''rapidly scale up technologies and policies that further accelerate the transition away'' from coal without carbon capture technology.

The debate at the summit over how quickly to abandon coal came at a particularly delicate moment for Mr. Biden, whose push for a major infrastructure package in a closely divided Congress may depend on the vote of one Democratic senator : Joe Manchin of coal-dependent West Virginia.

In a statement to the New York Times, Mr. Manchin took note of ''projections showing that fossil fuels, including coal, will be part of the global energy mix for decades to come'' and praised the Biden administration for recognizing the need to develop clean energy technologies.

But advocates for faster action said concerns about the placating Mr. Manchin appeared to have prevented more aggressive steps.

Other leading climate change advocates and diplomats called the overall climate package a mixed deal.

President Biden and other leaders said they would deliver $2 billion to help nations pivot away from fossil fuels, in what leaders hope will be a global transition to wind, solar and other energy that does not produce planet-warming carbon-dioxide emissions.

And they agreed to raise their contributions and meet an overdue pledge of mobilizing $100 billion a year to help poorer countries cut emissions and cope with the consequences of climate change, though firm dollar figures were not on the table.

A recent report from the International Energy Agency concluded that if the world is to stave off the most devastating consequences of global warming, major economies must immediately stop approving new coal plants and oil and gas fields.

Laurence Tubiana, a C.E.O of the European Climate Foundation who served as France's chief climate ambassador during the 2015 Paris negotiations, said she was pleased that nations would stop financing new coal projects without technology to capture and store emissions.

It will mean an end to virtually all funding for new coal, since carbon capture technology is nascent and not widely used.

''That leaves China to decide now if they want to still be the backers of coal globally, because they would be the only one,'' she said. But she said the finance package was lacking for developing countries, which are particularly vulnerable to floods, droughts and other impacts of climate crisis created by the industrialized nations.

The Group of 7 nations also backed Mr. Biden's sweeping infrastructure plan to counter China's Multi-trillion dollar Belt and Road Initiative. As part of that, countries promised to help the developing world rebuild from the Covid-19 pandemic in a way that takes climate change into account.

At the summit, the seven countries addressed biodiversity loss, calling it a crisis on the same scale as climate change.

They said they would champion a global push to conserve at least 30 percent of the planet's land and water by 2030 and would set up such protections within their own countries.

Those measures are needed, scientists say and the Group reiterated, to help curb extinctions, ensure water and food security, store carbon and reduce the risk of future pandemics.

Today, about 17 percent of the planet's lands and 8 percent of the oceans are protected, according to the United Nations.

Environmental groups welcomed the 30 percent commitment but emphasized the need for action, which required adequate financing. That is to be hammered out at a United Nations biodiversity conference that will be held in October in Kunming, China.

Because the world's remaining intact ecosystems and biodiversity hot spots are unevenly distributed , scientists emphasize that it's not enough for each country to carve out its own 30 percent.

Rather, countries should work together to maximize the protection of areas that will yield the best returns.

The World Students Society thanks authors Michael D. Shear, Lisa Friedman, and Catrin Einhorn.